Harare water problems not insurmountable

Guest Column: Tomas Persson

HARARE has experienced water problems for over two decades, with the authorities struggling to meet demand or mitigate against drought, as is the case this year. But the capital’s water problems, though well documented, are not insurmountable. Tomas Persson is a director with Aqua Matters, a company that specialises in providing industrial water solutions.

While attending the Water Infrastructure Conference in the beginning of June 2018, I became aware of the water situation in Greater Harare, both in relation to quality, but above all, quantity. The planned dams will take many years to construct and by that time, Harare will have faced a catastrophic water situation! The short-to-medium-term solution is to maximise the use of groundwater.

The study of a paper by Alfred Misi, who is part of the Upper Manyame Sub-Catchment Council, gave enough indication that our project of insitu remediation, which is the treatment of ground water to make it safe for human use and consumption and managed aquifer recharge (MAR), which is capturing rainwater to deliver the water to the aquifer is doable. It gives the idea that the aquifer for Harare is not very strong or does not hold very much water, but combined with the captured rainwater, it can produce the required volumes of water for Greater Harare.

The first person we contacted was Robert Mutepfa, acting permanent secretary for the Water ministry who introduced us to the Environmental Management Agency (EMA) and the town clerk of Harare, Hosea Chisango, but we received no responses from both authorities. In October last year, we got hold of the permanent secretary of water, who agreed to the problem of water in Harare, but when we sent a letter requesting for a mandate to commence the project, we never got feedback.

We also got hold of the chairman of the upper catchment board, who said they were not prepared to meet with me unless we had a project plan for our proposal. We explained to them that we needed information from relevant authorities on data of locations of boreholes, abstractions rate and qualities, and only then could we make a desktop study for the project plan, but no one assisted us. Currently, we have not gotten any response from anyone and there is no possibility to make any kind of project plan without the information we require.

Insitu remediation means treating water in the aquifer, which is ground water. It is different from water works where they use basins, pumps and many other structures. We do not construct anything. What we do inject into the aquifer is different substances like vegetable oil for denitrification of nitrates and oxidation using oxygen. What that means is capital expenses are very small because we do not build complex structures for the process as we just use sophisticated injectors. The strategy of MAR is that when you have rainfall, you reduce the speed of the water in the rivers by building many small dams of one to two metres. Depending on how dense the aquifer is, you might need to drill a hole so that the water goes where you want it to be stored (aquifer).

Project cost

In our operations we first work with the pilots, a part of which is fairly small and could cost a few hundred thousand dollars, just to show that a specific aquifer type in an area is capable of doing the processes we require, that is the insitu remediation and MAR. After the pilot, it will be easier for investors to fund the project. However, before we do anything of this, we need information that has to be released from relevant authorities, among them the municipality, city council and maybe the Local Government ministry on issues of borehole locations, abstraction rates and quality of water, to ascertain how large the area we can cover is. After that we can ascertain the costs which would likely be incurred.

Sustainable solution?

As a strategy, we store the water underground to avoid losses, therefore, making it an absolutely sustainable solution. What we do is more like a quick fix to the problem of water shortages, meaning we can address the problem in a short period of time. The idea of storing water in dams will probably take five to ten years to start seeing the results, and we know now that dams are not a good place in which to store water because of evaporation.

Kariba Dam is running at half capacity and within a couple of months, they are likely going to shut down all power plants because of evaporation and low rainfall. At the moment if you exclude the two dams being used in Zimbabwe, the amount coming from boreholes can be doubled or even tripled and, therefore, means at 100% aquifer recharge, it is highly-sustainable.

Assuming we get the mandate to start the project plan, it can take up to six months to develop a project and to get funding because we have to convince the investors that the project will be successful. When we start the project, it is difficult to state how long it would take to start seeing the end result (water) because while the installation process of managing aquifer recharge is very fast, we are also working with biological bacteria which takes time to populate. It can take up to six months to start producing the required water. In total, the results can be a year before water can get to the end user.

Comparing our proposal to the idea of storing water in dams, which can take five to ten years, is much more feasible and efficient than having treat polluted water.

 Tomas Persson is a director with Aqua Matters, a company that specialises in providing industrial water solutions. He was speaking to Rutendo Matanhike

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